Low Threshold Lasing from Silicon Mie Resonators

The unique electromagnetic response of high-index dielectric resonators with Mie resonances facilitates the selective enhancement and confinement of light, holding great promise for nanoscale lasing. However, up to now, nanolasing exploiting Mie resonances of individual Si nanowires has been limited to theoretical proposals. Here, we demonstrate a strategy to realize nanolasing with Si nanowires in the SOI platform. It is found that, by carefully tailoring the sizes of the Si nanowires, the Mie resonances of Si nanowires enhance the pumping/ emission fields, leading to continuous-wave lasing at room temperature with low threshold in the visible range. The lasing of a dye at the wavelength of 523 nm assisted by the Mie resonances of Si nanowire is demonstrated experimentally. It is shown that the lasing wavelength changes with the width of nanowire due to the different scattering peak from Mie theory. In addition, the quality factor Q of lasing modes can be affected by the thickness of silica shell which determines the interaction volume of the pumping light and dyes. The proposed strategy paves the way towards practical integrated nanolasers for single-photon sources and micro-display, which have potential applications of on-chip optoelectrical devices.